A spirolactone compound (1) designated Aranorosin has been isolated from a fungal strain Pseudoarachniotus roseus. ##STR2## The compound (1) reported to be an antibiotic and its derivatives (2) and (3) were disclosed by H. W. Fehlaber and T. Mukhopadhyay et al J. Am. Chem. Soc., 110, 8242 (1988).
Certain 3,4 substituted .beta.-lactones, exhibiting antihypercholesterolemic activity have been disclosed in U.S. Pat. No. 4,751,237 and copending application Ser. No. 021,848 filed Mar. 4, 1987 and Ser. Nos. 053,646, 053,774 filed May 26, 1987.